Overview
EN ISO 21569:2005 - "Foodstuffs - Methods of analysis for the detection of genetically modified organisms and derived products - Qualitative nucleic acid based methods" specifies laboratory procedures to qualitatively detect GMOs and derived products by analysing extracted nucleic acids. The standard focuses on PCR‑based amplification and gives general requirements, minimum performance criteria and confirmation steps to ensure comparable, accurate and reproducible results across laboratories. Although established for food matrices, it can also be applied to feed and environmental plant samples.
Key topics and requirements
- Principle: Qualitative detection of specified DNA target sequences using PCR; results are expressed as presence/absence relative to controls and method detection limits.
- PCR methods: Includes conventional PCR and real‑time PCR (where amplification and detection can occur simultaneously).
- Detection & confirmation: PCR products may be detected by gel electrophoresis or alternatives; identity confirmation can use restriction analysis, hybridization or DNA sequencing.
- Quality of nucleic acid extracts: Specifies that extracts must be of sufficient purity, integrity and amplifiability; PCR inhibition controls are required (see ISO 24276).
- Performance criteria & optimization: Reaction conditions (e.g., MgCl2, thermocycling) and sensitivity must be optimized and validated for each primer/system. The standard defines repeatability, reproducibility and other performance requirements.
- Annexed methods: Practical examples are supplied in Annexes A–D covering:
- Target‑taxon specific methods
- Screening methods (common GMO elements)
- Construct‑specific methods
- Event‑specific methods
- Intellectual property note: ISO advises that patent rights related to PCR technology may apply and that patent holders have indicated willingness to license under reasonable terms.
Applications and practical value
- Routine GMO screening of food ingredients and consumer products to support regulatory compliance and labeling.
- Investigative testing in feed analysis and environmental monitoring (plant samples).
- Method development and validation in food testing laboratories seeking standardized qualitative procedures.
- Use in quality assurance programmes to produce reproducible, defensible yes/no GMO results for suppliers, manufacturers and regulators.
Who should use this standard
- Food and feed testing laboratories
- Regulatory and enforcement agencies
- Quality assurance and compliance managers in the food industry
- Method developers and diagnostic kit manufacturers
- Environmental testing laboratories dealing with plant materials
Related standards
- ISO 21568 - Sampling for GMO analysis
- ISO 21570 - Quantitative nucleic acid based methods
- ISO 21571 - Nucleic acid extraction
- ISO 24276 - General requirements and definitions for nucleic acid based GMO methods
This standard is essential for reliable, standardized qualitative GMO detection using nucleic acid and PCR‑based methods in food and related matrices.
